Or did the studies put the cart before the horse. In that those studied were already at an increased risk before the Marijuana use and were self medicating.
All of the Psychologists or Psychiatrist, I have ever been around were Psychotics trying to find out what is wrong with themselves including my own brother with a Psychology degree.
These "studies" serve up the correlation-equals-causation junk science the authors should have unlearned in school. But the same FReepers who see through globull warming swallow this garbage hook, line, and sinker - because it fits their preconceptions.
This longitudinal study used the entire population of Denmark born since 1955 because their medical registries are that comprehensive.
They specifically controlled for the self medicating cart/horse issue by not including anyone diagnosed with schizophrenia up to one year after being diagnosed with a substance abuse disorder.